This document describes a smart door security system using a Raspberry Pi, PIR sensor, camera module, and Telegram app. The system works as follows:
1. When a person approaches the door, the PIR sensor detects their motion and triggers the camera module.
2. The camera module captures an image of the person and sends it to an Android device via the Telegram app. This notifies the homeowner that someone is at the door.
3. The homeowner can then unlock the door remotely from their phone if the person is known, granting them access. The system aims to provide remote monitoring and access control for homes using low-cost IoT devices.